Tool for reforming vacuum tube type contacts



June 9, 1964 G. A. GUILLOTTE ETAL 3,135,137

TOOL FOR REFORMING VACUUM TUBE TYPE CONTACTS Filed March 28, 1963 INVENTORS GUY A. GU/LLOTTE a NORMAN C.L. PROCTER A TTORNEYS,

United States Patent M 3,136,187v TOOL FOR REFORMING VACUUM TUBE TYPE CONTACTS Guy A. Guillotte, St. Bruno de Montarville, Quebec, and Norman C. L. Procter, Mount Royal, Quebec, Canada, assignors to Northern Electric Company Limited, Montreal, Quebec, Canada Filed Mar. 28, 1963, Ser. No. 268,638 Claims. (Cl. 8115) This invention relates to a tool for reforming vacuum tube contacts in vacuum tube sockets.

The tool of the invention is particularly intended for reforming the contacts of vacuum tube sockets of the type comprising a plurality of sleeve contacts mounted within a series of bores arranged in a circle in a block of insulating material having a comparatively large central bore. In the past, when such sockets failed to give good contact with the prongs of the vacuum tube, it was the custom to replace the malfunctioning socket or sockets.

V The replacement of such a socket entailed a considerable amount of labour as well as giving rise to annoying service interruptions. The extent of labour involved in this replacement operation made the operations expensive since it was first necessary to destroy all the soldered connections of the wiring to the contacts, then remove the socket retaining ring and the socket proper, replace the socket, remount the replacement socket and retaining ring, and once again solder the several connections.

With the tool of the present invention the contacts of. the socket can be reformed with the socket in situ, and the tedious breaking and remaking of the soldered connections is thus avoided.

The tool of the invention functions to reform the contacts by inserting into each of the small bores in the socket (each of which bores contains a multi-part contact), a tapered prong which forces the separated parts of the contact in each bore towards one another, thereby re-establishing the relative positioning of the parts of the contact in each small bore to a position in which they will make effective contact with'the prongs of a vacuum tube inserted in the small bores of the socket.

There is, of course, one such tapered prong for each of the small bores in the particular socket which the tool in question is intended to reform. The plurality of tapered prongs is carried by a member which is mounted upon the tool so as to be slidable longitudinally thereof. The nature of this member, and of the remainder of the tool, including the means for aligning and sliding the prong-carrying member, will be'described in greater detail later on, in conjunction with the accompanying drawings.

First, however, we wish to provide a general statement of the nature of the invention. The tool of the invention may be defined as an apparatus for reforming contacts in vacuum tube sockets comprising a shouldered rod means having a part which is passable through the central bore in a vacuum tube socket, a threaded sleeve mounted on said rod means, a member carrying a plurality of tapered prongs mounted on said sleeve so as to be slidable longitudinally thereof, and means for forcing said member, without rotating it relative to the sleeve of the socket being reformed, towards a socket through which said rod means has been inserted, said means comprising a threaded nut mounted on said sleeve in threaded engagement therewith, and means for rotating said nut.

In the accompanying drawings illustrating one embodiment of a tool according to the invention:

FIGURE 1 is an exploded view of the tool;

FIGURE 2 is a cross-section, on the line 2-2 of FIGURE 1, showing the application of the tool to the reforming of contacts in a socket, part of the tool being shown in the side elevation;

3,136,187 Patented June 9, 1964 FIGURE 3 is an end view taken on the line 33 in FIGURE 2;

FIGURE 4 is a cross sectional view taken on the line 44 in FIGURE 2; and

FIGURE 5 is an end elevation looking in the direction of the arrows 5-5 in FIGURE 2, but with the socket removed.

The tool of the invention is intended to be used to reform the contacts of a vacuum tube socket of the type shown at 10 in FIGURE 2. This vacuum tube socket is seen to consist of a ring 11 formed of insulating material and having a central bore 12, which is preferably tapered as illustrated in FIGURE 2. A plurality of comparatively small contact-mounting bores 13 are disposed in a circle which is concentric with the main bore 12. (Two of these bores '13 appear in FIGURE 2.) Each of the bores 13 contains a contact 14 having a wire-connecting tap 15 and two separated end parts 16 which are intended to embrace, and establish good electrical contact with, the metallic prongs of the vacuum tube. During use the separate end parts 16 may become spread apart so far that they will fail to establish good electrical contact with the prongs of the vacuum tube. It is failures of this type which the tool of the invention is intended to correct.

The illustrated embodiment of a tool according to the invention, and the manner which it is intended to be used, will now be described in detail.

The tool is made up of a pair of cooperating rod members 17 and 18, a sleeve 19 mounted by means of the members 17 and 18, a member 20 which is concentrically mounted on the sleeve 19 and carries a plurality of tapered prongs 21, a thrust washer 22 and a nut 23. .The member 29, the thrust washer 22 and the nut 23 are locked together by means of a split retaining ring 24 which is press fitted within a cylindrical outer sleeve 25.

The sleeve 19 is externally threaded as indicated at 26 and the nut 23 is internally threaded as indicated at 27. As best seen in FIGURES 4 and 5, the member 20 and the sleeve 19 have cooperating flattened surfaces 28 which serve to lock the member 20 against rotation relative to the sleeve 19, while permitting sliding of member 20 longitudinally of the said sleeve 19.

The rod member 17 is knurled at its outer end, as indicated at 29, to facilitate gripping, and is shouldered adjacent its mid-point, as indicated at 30. The rod 17 has a tapered portion 31 which is located just inwardly of the shoulder 30. This tapered portion 31 is complementary in shape and size to the bore 12 in the ring 11 of the socket 1i). Inwardly of the tapered portion 31, the rod member 17 is of relatively smaller solid cylindrical formation, and is externally threaded adjacent its inner end as indicated at'32.

The rod member 18 is also knurled adjacent its outer end, as indicated at 33, to facilitate gripping; and is provided at its inner end with a central bore 34 which is internally threaded, the threading being complementary to the external threading 32 on the inner'end of the rod member 17.

There is a second shoulder (indicated at 35 in FIGURE 2) on the rod member 17, this second shoulder being located at the point where the tapered portion 31 meets the smaller cylindrical portion. The sleeve 19 is concentrically mounted on the smaller cylindrical part of the rod member 17, and is held in position by being jammed between the shoulder 35 on the rod member 17 and the inner end of the rod member 18.

When using the rod, before the inner end of the rod member 17 is passed through the bore in the sleeve 19 and threaded into the bore 34 in the inner end of the rod member 18, the rod member 17 is first passed through the central bore (i.e. bore 13 in the socket ring 11 of the socket to be reformed) until such time as the tapered portion 31 of therod member has passed within the tapered central bore in the socket and the shoulder 30, on the rod member 17 has come to rest against the inner face of the socket. The two rod members 17 and 18 are then threadedly connected to one another, thereby jamming the sleeve 19 between the shoulder 35 on the rod 17 and the inner end of the rod 18 and also simultaneously clamping the socket between one end of sleeve 19 and the shoulder on member 17.

The nut 23 is provided with transverse grooves 36, and a nut driving member or wrench 37 is provided which has a bandle 37a. The inner end face 38 of the wrench 37 is provided with transverse projections 39 intended to co-operate with the grooves 36 in the nut 23. The wrench 37 is provided with a central bore 40 of slightly greater diameter than the outer diameter of the rod member 18 so that the wrench may be inserted over the end of the rod member 18 and moved generally coaxially along the rod until such time as the projections 39 can be caused to enter the grooves 36 on the nut 23.

The member 20 carrying the tapered prongs 21 is initially so mounted on the sleeve 19 that the tapered end of the prongs 21 will enter the contact-mounting bores 13 insocket ring 11 in the space between the end parts 16 of the contacts and the hub portion of the insulating ring 11. When the tool has been finally assembled about the socket 10 in the manner described above, the member 20 is forced toward the socket 10, thereby forcing the tapered prongs more deeply into the contact-mounting bores 13. The force which drives the member 20 toward the socket 110 is, of course, obtained'by turning the wrench 37 (with the projection 39 inserted into the grooves 36 in the nut 23). Thenut 23 can thereby be driven to the left (as viewed in FIGURE 2), and this inward driving of the nut 23 will, through the medium of the thrust washer 22, force the member 20 towards the left (once again, as viewed in FIGURE 2). When the member 20 is driven inwardly, it will not rotate, due to the provision of the flattened surfaces 28, but will simply slide longitudianlly relative to the sleeve 19.

As the tapered prongs 21 enter more deeply into the anchoring bores 13, the ends 16 of the contacts 14 will be forced into close proximity with one another, and, when the tapered prongs 21 are withdrawn from the bores 13, the ends 16 will be in a position where they will firmly grasp, and establish good electrical contact with, the prongs of any vacuum tube inserted in the anchoring ore.

Once the reforming operation has been completed, the prongs 21 of the member 20 may be withdrawn from the bores 13 in the socket 110 by turning the wrench 37 in the opposite direction, whereby the threaded nut 23 will move to the right, as'viewed in FIGURE 2. As this occurs, the nut 23, through the medium of the locking ring 24, will carry the member 20 (together with the thrust washer 22) t0 the right as viewed in FIGUREZ. Once the prongs 21 have been withdrawn from the bore 13, the tool can completely disassembled and withdrawn from the socket by breaking the threaded connection between the inner ends of the rodmembers 17 and 18, and withdrawing these members outwardly in opposite directions.

What we claim as our invention is: 1. An apparatus for reforming the contacts of vacuum tube sockets of the type comprising a plurality of sleeve 'contacts mounted within a series of bores arranged in a circle in a block of insulating material having a comparatively large central bore, said apparatus comprising rod, an externally threaded sleeve mountable on said first rod between the shoulder thereon and the inner end of said second rod, said sleeve being of such a length that it may be jammed endwise between the inner end of the second rod and the front face of a socket mounted on the first rod with its rear face against the said shoulder, a member carrying a plurality of tapered prongs non-rotatably mounted on said sleeve so as to be slidable longitudinally thereof, and means for forcing said member towards a socket through which the first rod has been inserted, said means comprising a threaded nut mounted on said sleeve in threaded engagement therewith, and means for rotating said nut.

2. Apparatus as defined in claim 1, including a thrust washer interposed between said member and said nut.

3. Apparatus as defined in claim 1, in which said member and said sleeve have contacting parts which are shaped to prevent rotation of said member relative to said sleeve while permitting the member to slide longitudinally of the sleeve.

4. Apparatus as defined in claim 2 including means by which said member, said thrust washer and said nut are locked against movement relative to one another longitudinally of the sleeve, but are permitted rotation relative to one another.

5. Apparatus as defined in claim 1, in which the outer ends of each of said rods are knurled or otherwise roughened to facilitate gripping.

References Cited in the file of this patent UNITED STATES PATENTS 

1. AN APPARATUS FOR REFORMING THE CONTACTS OF VACUUM TUBE SOCKETS OF THE TYPE COMPRISING A PLURALITY OF SLEEVE CONTACTS MOUNTED WITHIN A SERIES OF BORES ARRANGED IN A CIRCLE IN A BLOCK OF INSULATING MATERIAL HAVING A COMPARATIVELY LARGE CENTRAL BORE, SAID APPARATUS COMPRISING A SHOULDERED ROD HAVING AN EXTERNALLY THREADED END, SAID ROD BEING INSERTABLE THROUGH THE CENTRAL BORE IN THE SOCKET UNTIL THE REAR FACE OF THE SOCKET IS CONTACTED BY THE SHOULDER ON THE ROD, A SECOND ROD HAVING AN INTERNALLY THREADED LONGITUDINAL BORE AT ONE END THEREOF INTENDED FOR THREADED ENGAGEMENT WITH THE THREADED END OF THE FIRST ROD, AN EXTERNALLY THREADED SLEEVE MOUNTABLE ON SAID FIRST ROD BETWEEN THE SHOULDER THEREON AND THE INNER END OF SAID SECOND ROD, SAID SLEEVE BEING OF SUCH A LENGTH THAT IT MAY BE JAMMED ENDWISE BETWEEN THE INNER END OF THE SECOND ROD AND THE FRONT FACE OF A SOCKET MOUNTED ON THE FIRST ROD WITH ITS REAR FACE AGAINST THE SAID SHOULDER, A MEMBER CARRYING A PLURALITY OF TAPERED PRONGS NON-ROTATABLY MOUNTED ON SAID SLEEVE SO AS TO BE SLIDABLE LONGITUDINALLY THEREOF, AND MEANS FOR FORCING SAID MEMBER TOWARDS A SOCKET THROUGH WHICH THE FIRST ROD HAS BEEN INSERTED, SAID MEANS COMPRISING A THREADED NUT MOUNTED ON SAID SLEEVE IN THREADED ENGAGEMENT THEREWITH, AND MEANS FOR ROTATING SAID NUT. 